SEATTLE - Buying and selling goods to strangers is becoming increasingly popular around the holidays, but it can be an easy way to get scammed. A mom and her teenage son were robbed when they tried to sell a pair of brand new sneakers on OfferUp.

Watch the video as the teen in gray walks up to a lime green Dodge Charger with a shoe box in hand.

He is expecting the men in the car to hand him $315. The amount they agreed to for the shoes, but as he places it through the window the car takes off.

He says he exchanged several messages with the men in the car who seemed excited about buying the shoes.

"He seemed really, really trustworthy and I bought into it,” said Cyris.

They met in a public place for safety, the Target store at Northgate in Seattle. The teen’s mom says they asked the buyers to meet inside of the store, but the men asked the teen to come to the car in the garaged so they could look at the shoes.

"I just went with my feeling like ok I’m going to go get this money, but I didn’t think of consequences of the setting or why they’re like staying in the car, it’s just things to look out for next time,” said Cyris.

Police say if you’re buying or selling anything online and are meeting in-person with a stranger, the safest place for the exchange is the police station. Many have designated Internet Purchase Exchange locations that are under surveillance.

“I, myself, use OfferUp and I always go to a law enforcement agency. If that person doesn't want to go with you, or meet you at that location, that's a clue and that's a red flag that this might be somebody that's going to take advantage of you,” said Detective Melanie Robinson with Kent Police.

Cyris is trying to save to buy a car but says after this experience he won’t be turning to OfferUp for help.

"I think I'm just going to work hard for my own money,” said Cyris.

Silva says the men did hand her son only $30 which Cyris decided not to keep and donate to a local church.